Metalurgi v37 640

3.4 The comparison of Solid Product 
3.4.1
 
Percent Solid after Precipitation 
The results of the process with variable sodium 
silicate addition show that the more sodium 
silicate added, the more white precipitate is 
formed. According to the experimental data, the 
addition of sodium silicate from 13% to 67% 
stoichiometric shows a significant increase. 
There was a decrease in the formation of white 
magnesium silicate precipitate with the addition 
of between 67% and 80% stoichiometric. Figure 
7 shows that the accumulation of 67 percent 
stoichiometric solids yielded 27.46% and the 
accumulation of 80% stoichiometric solids 
yielded 24.25%. 
Because 100% stoichiometric sodium silicate 
with a magnesium ion has not been achieved, 
there should be no decrease in solids recovery 
based on the stoichiometric sodium silicate with a 
magnesium ion addition of between 67% 
stoichiometric to 80% stoichiometric. Several 
possibilities exist, including the reaction of 
sodium silicate and calcium ions to form calcium 
silicate in the mineral wollastonite [23]. The 
second possibility is that some magnesium ions 
become trapped in the gel and do not react with 
the other sodium silicates. 
Figure 7. The effect of adding sodium silicate to the single-
stage precipitation process on the increase in percent solid 
The solids formed in a multi-stage process are 
similar to those formed in a single-stage process 
(Fig. 8). 
Figure 8. The effect of the addition of sodium silicate on the 
multi-stage precipitation process on the increase in percent 
solid 
Figure 8 shows that the maximum solid 
percent formed in the multi-stage process is 
24.72%, while in the single-stage process the 
percent solid obtained is 24.25% (Fig 6). The 
comparison of multi-stage and single-stage 
experimental results shows that the single-stage 
process 
stores 
relatively 
more 
lithium, 
magnesium, and other ions than the multi-stage 
process.

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